Tennessee Evaluation of New Maturity Technology: Laboratory Investigation (05-0162) - MP-15**
Lewis Keith Crouch, Tennessee Technological University

A project was conducted to evaluate the ability of new maturity technology to predict compressive strength development of Tennessee rigid pavements. The information generated in the project will assist the Tennessee Department of Transportation (TDOT) in making a decision on allowing the new maturity technology to be used in lieu of cylinder compressive strength results for opening new PCC pavements to traffic. In the laboratory portion of the evaluation, one-hundred-twenty (4 groups of 30 each) 6- by 12-inch (152- by 305-mm) cylinders cured at different temperatures were used to validate the maturity relationship over the range of TDOT Portland Cement Concrete (PCC) temperature specifications for curing. The difference between compressive strengths of 6- by 12-inch (152- by 305-mm) cylinders cured in the laboratory at the same maturity index for curing temperatures between 45 and 90°F (7 and 32°C) is in the range of 3.8 to 12.5 percent for maturity indices of 2,400 to 22,000°C-hours. At lower maturity indices, the compressive strength difference in percent was much greater (29.7 to 60.7).